Statement of the Invention
The invention relates to a contact for a contactor assembly, and more particularly, to a contact which has a short length suitable for high frequency applications and which applies a minimal force to electrical contact pads on products being tested or connected thereto.
Description of the Prior Art
In U.S. Pat. No. 3,806,801, filed Dec. 26, 1972 and issued Apr. 23, 1974, a contactor assembly having what are called buckling beam probes or contacts is disclosed in which the probe contactor has each of it's probes formed with a length many times it's cross-sectional area so that the probes buckle or deflect when a predetermined axial load is applied thereto. This enables the same force to be exerted on each of a plurality of pads on a semiconductor chip regardless of the deflection of the probes produced by variations in the heights of the pads. The forces for contacting the pad must be kept small so that the pads are not damaged. Accordingly, this prior art contact or probe was made sufficiently long with respect to it's cross-sectional area such that the force applied to the pads would be determined by the resistance to buckling of the beam. The long buckling beam provides a small force plus a relatively uniform force throughout it's deflection or buckling range. This prior art probe was contained at the upper end and was free to move only vertically at the lower end and was constrained to buckle in a given direction by an upper and lower die member. These long contacts were not adaptable to high-frequency operations because of their length. Shortening the contact or probe increased the force applied to the pads thereby increasing the amount of pad damage.
Accordingly, it is the main object of the present invention to provide a short contact for a contactor assembly which is operable in high frequency applications and which provides minimal forces on connector pads.
It is a further object of the present invention to provide a contact for a contactor assembly which includes a pivoting and deflection operation combination to produce minimal contacting forces.
It is another object of the present invention to provide a contact for a contactor assembly in which the pre-curved central portion is flattened to produce a deflection characteristic having less deflection resistance.
It is yet another object of the present invention to provide a contactor for a contact assembly in which the ends thereof are offset from one another within the plane including the radius of curvature of the central section so that the deflection direction is essentially predetermined and radial pivoting is absolutely minimized which also contributes to high frequency electrical conformity and permits utilization on very close centers.
Another object of the present invention is to provide pivotal contact wipe at the interface between the balled upper end of the contact and the associated electrical conductive elements.
Another object of this invention is to provide minimal controlled contact wipe at the interface area between the lower end of the contact and the electrical pad on the product being tested due to essentially linear motion of this contact end.